Disks around main sequence stars
IRAS discovery of IR excess around main sequence stars (Excess in Vega by Aumann et al, 1984).
The dust disk around ?-Pictoris has been imaged from 2.”5 to 25”. Models predict a void of matter in the center.
ISO observed a volume limited sample (Dominik et al. 1999) ?
- ~20% of stars show IR excess.
- Disks are more frequent in young stars than in old ones, however there is no trend of fractional IR luminosity with age.
- IR Excess appears at lᡌ mm in some cases
To be addressed with MID IR imaging:
- high resolution at 10 mm to study the inner part of the disks
- detection of disks at 20mm
- morphology of disks, size of inner hole.